The present invention relates generally to an improved system for control of moisture migration through the soil along, adjacent, and under paved roadbeds, and more specifically to an electrolytic means for the control of such moisture migration. The electrolytic means includes the provision of anodes and cathodes arranged in either spaced apart or oppositely disposed relationship along the paved zone, the anodes being formed from a crushed rock high in calcium and magnesium oxides, such as dolomitic limestone or basalt, with the cathodes being formed of electrically conductive carbon, and preferably metallurgical coke. With this arrangement of components, it has been found that moisture migration may be controlled through the soil structure disposed between the individual anodes and cathodes.
In the past, electro-osmosis has been utilized for control of moisture conditions in soil, such as, for example, for controlling the leeching of certain undesirable salts from soil structures. Normally, these systems have included the intentional disposition of water in the control area, with the application of an electrical field being utilized to exert an affect upon the soil, including affecting the salts which may be present in the soil. The present arrangement is utilized for the control of undesired moisture which may be present beneath roadbed surfaces, and with improved drainage of moisture from said areas.
In certain soils, such as, for example, clay soils and the like, it has been found that the application of an electrical field through the soil may enhance the ability of the soil to dispose of water and water particles.
In the application of the present concept to treatment of roadbeds, it is readily appreciated that damage to roadbeds occurs when the roadbed undergoes freeze-thaw cycles in the presence of excessive quantities of moisture. This moisture contributes to the formation of frost heaves and the heaves in expansive clay or shale materials in the roadbed, those heaves requiring extensive repair to restore the surface. The arrangement of the present invention enables the loss or dissipation of moisture from the area beneath the roadbed, thus decreasing the tendency toward frost heaves and the heaves from expansive clay or shale material.